According to the prior arts, a stylus is required to have a power supply, or an externally transmitted induced electrical field to supply energy such that the stylus could be operated after obtaining the energy, and this stylus can only be used in electromagnetic touch technology. In accordance with the aforementioned technology, if there is a power supply unit inside the stylus, regardless of the type of energy storage device, such as a rechargeable battery or a supercapacitor, used, it will need to be charged or replaced, which will cause a life-cycle problem. If it is a passive electromagnetic stylus, the host needs to release an electromagnetic field with high energy to allow the stylus to induce this energy in order to operate, and the power consumption of this method is higher than that of a stylus with an energy storage device.
Thus, a way to improve upon the existing technologies to make a stylus that does not depend on an internal power supply or an internal energy storage device is worthy of further research and improvement.
Keeping the drawbacks of the prior arts in mind, and by employing persistent and robust experiments and research, the applicant has finally conceived a projective capacitive stylus and a controlling method thereof.